Hold-down device for machines for rotating cylindrical articles



N .24, 95 J; 1.. COOPER ErAL 2,913,784

[ HOLD-DOWN DEVICE FOR MACHINES FDR ROTATING CYLINDRICAL ARTICLES FiledJan. 17, 1957 '6 Sheets-Sheet 1 .v INVENTORS JACOB L. COOPER KENNETH R.DAN/EL JAMES 6. LOWER) ATTORNEYS Nov. 24, 1959 J. L. COOPER A 8HOLD-DOWN DEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLES FiledJan. 17, 1957 6 Sheets-sheaf 2 INVENTORS JACOB 1.. 000, 50 KENNETH R.mam/1. JAMES 0. LOWER) ATTORNEYS BY/M/ Nov. 24, 1959 J. L. CO0PER ETALHOLD-DOWN DEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLES 6 sheetssheet 3 Filed Jan, 17,1957

INVENTORS JACOB L. COOPER KENNETH R. DAN/EL JAMES 6. LOWE RY ATTORNEYSJ. 1.. COOPER ET AL 2,913,784

HOLD-DOWN DEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLES 6Sheets-Sheet 4 M ORLY MEIR W 00 L 0 E s O E GM M M hnu 2 v o 1 1 n 9%JHH I k vu m n mm m 2 mm M M mm un r W wk R k R 0 m mo R 0 mm o L Q. T vI I Q o o Y mm Q 4 Q v\ an Q Mm mu 1 mw I N l l .ll ww IIlIHkMTI & Q NuT llll KVTIQA \w R Q m mm 3 .Q\ G mklmxx 8 mm v T m wk w .i. Q m l Nov.24,1959

Filed Jan. 17. 1957 BY I M MZZZK ATTORNEYS 9 J. COOPER ETAL HOLD-DOWNDEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLES Filed Jan. 17.1957 6 Sheets-Sheet 5 INVENTORS 7 JACOB L. COOPER KENNETH R DAN/EL JAMESO. LOWER) finer-n4, MM

ATTORNEY 5 Nov. 24, 1959 L. COOPER ETAL I 2,913,784

HOLD-DOWN DEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLES FiledJan. 17. 1957 Y a Sheets-Sheet 6 AIR HYDRAULIC 00 FLUID FREE- FLOWRESTRIOTEDFLOW F R E 5- FLO VI RESTRIGTED+F LOW INVENTORS JACOB L.COOPER KENNETH R. DAN/E L JAMES 6. LOWER) ATTORNEYS United States Pate te HOLD-DOWN DEVICE FOR MACHINES FOR ROTATING CYLINDRICAL ARTICLESApplication January 17, 1957, Serial No. 634,720

Claims. (Cl. 22-65) This invention relates to apparatus for rotating atrelatively high speeds generally cylindrical articles of substantialmass, such as centrifugal'casting molds, metal pipes and the like, andmore particularly concerns a safety device for restraining a spinningarticle against accidental ejectment from the apparatus while it isbeing rotated. j

Inasmuch as the device of the present invention is especially welladapted for use with the high speed spinning machines employed forrotating molds and pipes in the manufacture of centrifugallycast metalpipe, the following disclosure will be directed primarily to thisparticular application of the inventive t concept. By so doing, however,it is not intended to limit the scope of the invention to mechanism forrotating pipe casting molds or. pipes, because it will be evident thatthe apparatus is useful wherever means are needed to hold a rotatablebody down on rollers or similar spinning elements. r j a The principalobject of the invention is to provide an improved restraining mechanismfor preventing a rapidly spinning object from accidentally jumping offthe rollers or, other members by which it is being rotated.w

Another object is the. provision of a hold-down device of the characterdescribed which is readily adjustable for use with centrifugal castingmolds, pipes and other cylindrical'articles of different diameters.

A further object of the invention is to provide a mold or pipespinningmachine with a hold-down mechanism of novel construction theoperation of which is interlocked with that ofthe means whereby themolds or pipes are delivered to and discharged from the rotatingmechanism..

Still another object is the provision of unique means for moving therestraining elements of a hold-down device of the character describedinto an operative posi tion wherein they obstruct bodily movement of anarticle while it is. spinning and then returning them to an inoperativeposition wherein they do not interfere with delivery and discharge ofarticles to and from the spinning mechanism. 7

These and other objects, including the provision of a hold-down devicewhich is normally out of contact with the rotating article, will appearmore fully upon consideration of the detailed description of theembodiment of the invention which follows. In this connection, althoughonly one specific form of apparatus is described and illustrated in theaccompanying drawings, it is to be expressly understood that thesedrawings are for purposes of illustration only and are not to beconstrued as defining the limits of the invention, for which latterpurpose reference should be had to the appended claims.

In the drawings, wherein for illustrative purposes the articles to berotated are shown as molds or flasks of the type commonly used forcentrifugally casting bell and spigot cast metal pipe, and wherein likereference characters indicate like parts" throughout the several views:

ice

Fig. 1 is a plan view of a known type of mold rotating apparatusembodying one form of hold-down mechanism according to the presentinvention, certain parts being broken away or shown in section along theline 1-1 in Fig. 4 and the central portion of the mold on the spinningrollers being omitted so as to more clearly illustrate certainstructural features of the machine;

Fig. 2 is a side view of the apparatus of Fig. 1, partially in sectionalong the line 22 in Fig. l; a

Fig. 3 is a fragmentary plan view of part of the hold-down mechanismwhich is broken away in Fig. 1;

Fig. 4 is across section taken substantially on line 44 in'Fig. 1,showing the means by which molds are delivered to and discharged fromthe rotating mechanism, the parts being shown in the positions occupiedwhen one mold is being discharged from and another mold is beingdelivered to the machine, and when the hold-down mechanism is set toaccommodate a mold of relatively large diameter;

Fig. 5 is a cross-sectional view similar to Fig. 4, but showing theparts in the positions occupied when a mold is being rotated;

Fig. 6 is a fragmentary cross section taken substantially on line 6-6 inFig. 1, showing the means by which the hold-down mechanism may beadjusted to accommodate molds of different diameters;

Fig. 7 is an enlarged view similar to Figs. 4- and 5, but omitting themold delivery and discharge means and indicating diagrammatically therelative positions of the elements of the hold-down mechanism when saidmechanism is adjusted to accommodate molds for casting six differentsizes of pipe ranging from 12" to 24 in diameter; and

Fig. 8 is a schematic diagram of the control system by which operationof. the hold-down mechanism is interlocked with that of the molddelivery and discharge means.

As stated above, the hold-down device of the presen of a mold liningmachine of the character disclosed in the copending application ofKenneth R. Daniel et al., Serial No. 555,934, filed December 28, 1955,now Patent No. 2,873,716.

As shown in Figs. 1-5, the mold rotating mechanism comprises a pluralityof spinning rollers 11 adapted to support a substantially cylindricalarticle, such as a centrifugal casting mold 12, in a horizontal positionand to rapidly rotate the mold about its axis while any desiredoperation is being performed, such as lining the mold or casting a pipetherein. The rollers 11 are mounted in two sets on shafts 13 and 14which extend parallel to the axis of the mold and are journaled inbearings 15 mounted on a stationary base 16 suitably fixed to themachine foundation. In the embodiment illustrated, shaft 13 is adaptedto be driven in any suitable manner, as by a variable speed motor (notshown), while shaft 14 is an idler, the rollers on the latter shaftderiving their rotation from the mold 12 which in turn is frictionallydriven by the rollers on shaft 13. Shaft 13 is also provided with aflanged wheel 17 which receives the guide flange 18 of mold 12 and holdsthe mold against movement in an axial direction during its rotation.

In order to properly control the delivery and discharge of molds to andfrom spinning rollers 11, the mold rotating mechanism includes a pair ofparallel, axially spaced detent-guide arms 19 which control the delivery2,913,784 Patented Nov. 24, 1959 kickout arms the primary purpose ofwhich is to eject the molds from the machine after the lining, castingor other operation has been completed.

As indicated in Figs. 1, 4 and 5, kickout arms 20 are fixed to the endsof a torque tube 21 which is mounted for oscillatory movement about afixed axis parallel to the axes of spinning roller shafts 13 and 14 at aposition beneath the ends of mold run rails 22 at the discharge side ofthe machine. The upper surface of each kickout arm 20 is of bent shape,having a portion 23 which is substantially tangent to the upper surfaceof torque tube 21 and a second portion 24 which is inclined downwardlyrelative to radially extending portion 23 and terminates in an upwardlyextending pointed end portion 25. As shown in Fig. 5, the pointed endportions 25 project slightly beyond the vertical axial plane of mold 12,toward the side of the machine from which the molds are loaded, when themold is in spinning position on rollers 11.

Each of detent-guide arms 19 is provided with a clevisshaped inner endpivotally connected to the free end of the associated kickout arm 20 bya pin 26 at a point just below the junction between pointed end portion25 and inclined portion 24 of the kickout arm, and is also of irregularshape. As shown best in Fig. 4, the upper surface of each detent-guidearm 19 is bent at substantially the same angle as the upper surface ofkickout arm 20, having a portion 27 at. the outer end of the arm whichis inclined downwardly with respect to the portion 28 at the inner endof said arm. The bottom edge of each detent-guide arm 19 rests on aflanged roller 29 rotatably mounted in a bearing bracket 30 fixed tobase 16. Rollers 29 engage the bottom edges of detentguide arms 19 atpoints substantially directly beneath the junctions between surfaces 27and 28, and support said arms in a position such that said junctions liein approximately the same plane as the rolling surfaces of mold runrails 22. The two detent-guide arms 19 are interconnected by a tie tubeor rod 31 at points intermediate the axes of flanged rollers 29 and theinner ends of said arms where they are pivoted to kickout arms 20, tietube 31 extending parallel to torque tube 21.

Fixed to torque tube 21 intermediate its ends is a radially extendingoperating arm 32 which lies in substantially the same plane as kickoutarms 20 and is pivotally connected at its inner end to the upper end ofthe piston 33 of a hydraulic cylinder 34. Cylinder 34 extends downwardlythrough a central opening in base 16 and is provided at its lower endwith a base cap 35 which is pivotally connected to a supporting bracket36 fixed to the machine foundation.

When a mold is in rotating position on spinning rollers 11 (see Fig. 5),piston 33 of hydraulic cylinder 34 is in its fully retracted positionand detent-guide arms 19 and kickout arms 20 form a wide V with theirupper surfaces completely out of contact with the lower surface of mold12. At this time, the outer ends of detentguide arms 19 project upwardlyabove the rolling surfaces of rails 22 in such position as to preventthe next mold on the delivery side of the machine from entering the moldrotating mechanism.

Upon completion of the lining, casting or other operation during whichrotation of the mold has been effected by rollers 11, the mold isejected or discharged from the machine by so admitting hydraulic fluidto cylinder 34 as to raise piston 33 to the uppermost position permittedby adjustable stop nuts 37 threaded on rods 38 which depend from theupper end of said piston and pass through openings in the cylinder head.The upward motion of piston 33 is transmitted by operating arm 32 totorque tube 21 and results in a counterclockwise rotation of the latterand movement of kickout arms 20 to the position indicated in Fig. 4. Askickout arms 20 are raised from the position shown in Fig. 5, theirpointed end portions 25 and inclined surfaces 27 come into conpersonnel.

tact with the surface of mold 12 at points on opposite sides of thevertical axial plane thereof, raise the mold, and then, as inclinedsurfaces 27 rise above the level of the rolling surfaces of rails 22,roll the mold off the kickout arms and onto said rails.

Due to the pivoted connection between kickout arms 20 and detent-guidearms 19, elevation of the former also raises the inner portions of thelatter to a substantially horizontal position, level with rails 22, andlowers the outer ends thereof below the rolling surfaces of the rails.The next mold in line may then roll into the machine to the positionindicated in broken lines in Fig. 4, where the pointed ends of kickoutarms 20 hold the mold until it is lowered onto'rollers 11 when hydrauliccylinder 34 is exhausted and piston 33 returns to the retracted positionshown in Fig. 5. As the inner ends of detent-guide arms 19 are raised byvirtue of their pinned connection with the ends of kickout arms 20,rollers 29 permit arms 19 to adjust their positions accordingly, formingin effect movable fulcrums for said arms.

As will be explained hereinafter in connection with the control systemshown diagrammatically in Fig. 8, retraction of piston 33 isaccomplished automatically as the result of actuation of a kickout downlimit switch S1 which is positioned alongside one of rails 22 closelyadjacent the end of said rail from which the molds roll into thespinning machine, and the operating lever of which is depressed by themolds as they roll thereover.

Although the occurrence is rare, it sometimes happens that a mold beginsto bounce as it is rotated by the spinning mechanism and may beaccidentally thrown out of the machine with consequent damage to themold or other machinery and possible personal injury to plant In orderto prevent such accidents, means must be provided for positivelypreventing the mold from leaving the machine during the spinningoperation. The present invention provides a safety mechanism for thispurpose which is characterized by its adjustability to accommodate moldsof different sizes, by its adaptability for automatic, interlockedoperation in cooperation with the spinning mechanism, and by the absenceof contact with the rotating mold during normal operation.

In the embodiment illustrated, the safety mechanism comprises a pair ofangular hold-down arms 39 located at the discharge side of the machinewhich are movable into and out of mold restraining position by anactuating assembly consisting of a torque tube 40, a pair of liftingarms 41 fixed to the ends of tube 40, and an actuating arm 42 also fixedto tube 40 intermediate its ends. The path of movement of hold-down arms39 is established by a second assembly consisting of a pivot arm 43, apivot tube 44 to which arm 43 is fixed and which extends betweenhold-down arms 39, and a pivot shaft 45 which extends axially throughand is keyed to tube 44 and on the ends of which the hold-down arms arepivotally mounted. The free end of arm 43 is bifurcated and pivotallyconnected to the upper end of a vertically movable pivot member 46 theposition of which is adjustable so as to vary the height of the pointabout which the oscillatory movement of hold-down arms 39 takes placeupon actuation by the means next to be described.

As is shown best in Figs. 1 and 2, the assembly of torque tube 40,lifting arms 41 and actuating arm 42 is pivotally mounted on a pivotplate 47 which is fixed to one of the supporting I-beams 48 of themachine base 16 in a vertical plane slightly offset from that of torquetube 21 of the kickout mechanism. To this end, pivot plate 47 isprovided adjacent its ends with a pair of horizontally projecting lugs49 carrying pivot pins 50 on which are journaled the ends of liftingarms 41. In the embodiment illustrated, each of lifting arms 41 isformed of a piar of parallel, spaced apart pieces united by transverselyextending spacers 51 which are welded thereto intermediate the ends ofthe arms so as to provide bifurcated arm ends to receive pivot lugs 49.At the opposite extremities .of lifting arms 41, the bifurcated endsthereof receive the lower ends of hold-dowmarms 39 which are pivotallyconnected thereto by pivot pins 52.

Actuating arm 42, which is also of bifurcated construction, is welded orotherwise fixed to torque tube 40 in substantially the same plane aslifting arms 41, and is pivotally connected at its free end to the upperend of the piston 53 of a hydraulic cylinder 54 which provides theactuating force of the holddown mechanism. Like cylinder 34 of therotating mechanism, cylinder 54 .is mounted in a generally verticalposition, being provided at its lower end with a base cap 55 which ispivotally connected to a supporting bracket 56 fixed to the machinefoundation, and is adapted to raise piston 53 from the retractedposition shown in Fig. 4 to the elevated position of Fig. which isestablished by adjustable stop nuts 57 threaded on rods 58 dependingfrom the upper end of said piston and passing through openings in thehead of cylinder 54. The flow of hydraulic fluid to and from cylinder 54is controlled automatically in predetermined relationship with the flowof fluid to cylinder 34 by the system illustrated in Fig. 8 ashereinafter described.

In order to guide the hold-down arms in the proper path and to theproper elevated position to accommodate the size of mold being rotated,arms 39 are pivotally journaled or fulcrumedon the ends of pivot shaft45, and the end of pivot arm 43 opposite its connection to pivot tube 44is journaled on the ends of a pin 59 which is carried by and fixed tothe upper end of the vertically adjustable pivot member 46. Pivot arm 43and lifting arms 41 thus form with the lower portions of hold-down arms39 a variable motion linkage having one permanently fixed pivot definedby pivot pins 50 and a second normally stationary, but verticallyadjustable pivot provided by pin 59.

The means by which the vertical positions of pivot member 46 and pin 59may be adjusted are shown best in Fig. 6. In the form there illustrated,pivot member 46 is slidably supported in a guide member 60 mounted onpivot plate 47 intermediate the ends thereof, and is provided at itslower end with a vertically extending, internally threaded bore 61 intowhich extends the upper threaded end of a screw shaft 62. The lowerportion of shaft 62 is journaled in a suitable thrust bearing 63 and isconnected by a coupling 64 of any suitable type to the output shaft 65of a reducing gear drive 66. The input shaft 67 of reducer 66 isdrivably connected by a coupling 68 to a torque motor 69 which isreversible in operation and adapted to be manually controlled by theoperator of the machine. The reducing gear drive 66 and the threadedconnection between shaft 62 and bore 61 of pivot member 46 are soconstructed that, when torque motor 69 is energized to rotate screwshaft 62 in the desired direction, pivot member 46 is either raised orlowered so as to vary the vertical position of pivot pin 59 which formsa center about which hold-down arms 39 move in space when raised andlowered by'lifting arms 41 upon operation of actuating cylinder 54.

In order that the machine operator may readily set the hold-downmechanism to accommodate a mold of any specific diameter, means areprovided by which the operator may quickly and accurately position pivotmember 46 at the proper elevation. In the embodiment illustrated,adjustment of the vertical position of pivot member 46 is accomplishedby the use of a stepped bar 70 which is longitudinally slidable onflanged guide rollers 71 through a vertically elongated slot 72 formedin the upper portion of pivot member 46 intermediate pivot pin 59 andinternally threaded bore 61. Rollers 71 are journaled on stub shafts 73which are suitably mounted in supporting brackets 74 carried by pivotplate 47. The steps on bar 70 are formed on the lower surface thereof atelevations corresponding to the different diameters ofmolds which themachine is adapted to rotate, and are provided with replaceable shims 75which permit accurate adjustment 6 of the mechanism. The bottom surfacesof shims 75 form. stops against which the base of slot 72 in pivotmember 46 is adapted to abut when the pivot member has been elevated tothe proper position.

Bar 70 may be adjusted to bring into position in slot 72 the proper stepfor the size of mold to be rotated by first'energizing torque motor 69so as to rotate screw shaft 62 in a counterclockwise direction andmovepivot member 46 to its lowermost position, at which time the base ofslot 72 is below the shim 75 of the step corresponding to the smallestmold to be accommodated, e.g., a 12" mold in the embodiment illustrated.Stepped bar 70 may then be moved in either direction on guide rollers 71by means of a hydraulic adjusting cylinder 76v having its piston 77connected to one end of bar 70. Operation of cylinder 76 and piston 77may be controlled manually by the operator of the machine in anysuitable manner, as by means of a push button operated, solenoid airvalve and a four-way hydraulic valve for controlling the flow ofhydraulic fluid to cylinder 76, which controls have been omitted fromthe drawings in the interestv of simplicity. In order to indicate whichstep of bar 70 is positioned in slot 72 at any particular time, the barmay be provided with a horizontally extending arm 78 having a pointer atone end which registers with an indicator plate 79 carrying index markscorresponding to the various steps of bar 70 and the sizes of moldswhich the machine is adapted to handle, and suitably mounted on themachine base 16 in a position where it can be readily ob-. served by theoperator.

When stepped bar 70 has been moved to a position corresponding to thesize of mold to be rotated, torque motor 69 is again manually energizedby the operator so as to rotate screw shaft 62 in a clockwise directionand raise pivot member 46 until the base of slot 72 comes into abutmentwith shim-75. of the step then located in the slot. With a torque motorand reducing gear drive of suitable character, the operator candetermine when the pivot member has reached the desired elevation bysimply watching the coupling 68 between the motor and reducing gear andopening the motor circuit when rotation of the coupling stops.

After pivot member 46 has been adjusted to the proper position in themanner above described, so as to set the hold-down mechanism toaccommodate a mold of the selected diameter, hold-down arms 39 may beraised to their up or mold restraining position by supplying fluid tothe bottom end of actuating cylinder 54 and thereby elevating piston 53to the uppermost position permitted by stop nuts 57. The verticalmovement of piston 53 rotates the integral assembly of actuating arm 42,torque tube 40 and lifting arms 41 about the permanently stationarypivotal axis of the torque tube and lifts the lower ends of hold-downarms 39 through a fixed are about said axis as center. However, the pathof movement of the portions of hold-down arms 39 above their lower ends,and the final up position of the upper ends of said arms, are determinedby the elevation of adjustable pivot member 46 and pivot pin 59 whichprovide the second normally stationary pivot of the arm moving linkageand establish the center of the arc through which move the pivotalconnections between arms 39 and pivot shaft 45.

When it is desired to discharge the mold from the: machine, the flow ofhydraulic fluid to actuating cylinder 54 is reversed so as to movepiston 53 downwardly to the bottom of its stroke and thereby return theholddown arms 39 to the retracted or inoperative position illustrated inFig. 4. The mold may then be ejected from the rotating mechanism byactuation of kickout cylinder 34 in the manner previously described.

As indicated in Figs. 1, 4, 5 and 7, hold-down arms. 39 are T-sh'aped incross section, with the transversely extending portion of the T formingthe lower or mold obstructing surface of the arms, and are so'formedthat the portions above their connections to pivot shaft 45 are inclinedat an angle of approximately 45 with respect to their lower portions,while their upper or tip ends have an additional inclination ofapproximately 22 /z in the same direction. The shape of hold-down arms39, the dimensions of the linkage by which they are raised and lowered,and the adjustable positions of the movable pivot provided by member 46and pin 59 are so designed that, when the hold-down arms are in theirretracted or inoperative positions, their upper ends lie below therolling surfaces of mold run rails 22 so as not to obstruct the path ofdischarge of molds from the machine, whereas in their elevated oroperative positions, they obstruct bodily movement of a rotating moldboth upwardly and laterally in the direction of discharge, but at thesame time provide a clearance of approximately 4" between the uppersurface of the mold and the overlying upper ends of the arms. In thisconnection, it should be noted that the stroke of piston 53 of actuatingcylinder 54 is constant for all sizes of molds, so that actuating arm42, torque tube 40, lifting arms 41 and the lower ends of hold-down arms39 rotate through a constant arc, although the upper portions of arms 39move in a different path for each different size of mold due to theadjustment of pivot member 46.

Although it is obvious that the hold-down mechanism of the presentinvention may be manually controlled independently of the rotatingmechanism, the hydraulic actuating means of the two mechanisms arepreferably interlocked and electrically controlled by a suitable systemof switches and valves, such as that'schematically illustrated in Fig.8.

As shown, the flow of hydraulic fluid to and from kickout actuatingcylinder 34 and hold-down actuating cylinder 54 is controlled by afour-way two-position valve 80 which may be operated pneumatically by asolenoid actuated pilot valve 81. The hydraulic connections betweenvalve 80 and cylinders 34 and 54 are so arranged that, when the piston33 of kickout cylinder 34 is in the extended position illustrated inFig. 4, which so positions detent-guide arms 19 and kickout arms 20 asto permit a mold 12 to roll from rails 22 into the rotating mechanism,piston 53 of hold-down cylinder 54 is retracted so as to lower hold-downarms 39 beneath rails 22 at the discharge side of the rotating mechanismand permit the previously rotated mold to leave the machine. When theparts are so positioned, the solenoid or pilot valve 81 is energizedfrom a suitable power source through normally closed kickout down limitswitch S1 and a second switch S2 which may be operated either manuallyor automatically at predetermined times in the cycle of the apparatus ofwhich the rotating mechanism is a part. For example, in the case of amold lining machine of the character disclosed in the previouslymentioned Danel et al. application, Serial No. 555,934, the

switch S2 may be operated automatically by the movable car on which thelining trough is carried.

As a new mold enters the rotating mechanism, it rolls over and openskickout down switch S1 to deenergize the solenoid of pneumatic pilotvalve 81 which in turn actuates the four-way valve 89 so as to reversethe flow of hydraulic fluid to cylinders 34 and 54, thereby loweringpiston 33, detent-guide arms 19 and kickout arms 20 and raising piston53 and hold-down arms 39 to the positions shown in Fig. 5. Asdetent-guide arms 19 and kickout arms 20 are lowered and deliver themold onto spinning rollers 11, hold-down arms 39 are moved into their upposition wherein they positively restrain the mold against accidentalejectment from the spining mechanism.

After the mold has been rotated for the desired length of time, switchS2 is closed either manually or automatically to again energize thesolenoid of pneumatic pilot valve 81 and return hydraulic valve 80 toits original position wherein fluid is so supplied to cylinders 34 and54 as to retract piston 53 of hold-down actuating cylinder 54, therebylowering hold-down arms 39 to their down position, and to simultaneouslyextend piston 33 of kickout cylinder 34, thereby elevating detentguidearms 19 and kickout arms 20 to eject the mold from the rotatingmechanism.

Although the electrical circuit for controlling the solenoid of pilotvalve 81 through switches S1 and S2 has not been shown in detail in Fig.8, it will be understood that any suitable means may be employed formaintaining the solenoid deenergized throughout the time that a mold isbeing lowered onto and rotated by spinning rollers 11, but otherwiseenergized as long as the machine is in use.

In order to avoid interference between hold-down arms 39 and molds 12 asthe latter are lowered onto and raised from spinning rollers 11, it isnecessary to carefully control the relative speeds of movement of thepistons 33 and 53 of cylinders 34 and 54, respectively. For example, thespeed of the upward or extending movement of piston 53 of hold-downactuating cylinder 54 must be slowed relative to the downward orretracting movement of piston 33 of kickout cylinder 34 sufliciently toinsure that the mold has been lowered onto spinning rollers 11 beforehold-down arms 39 reached their up position. Furthermore, the speed ofthe upward or extending movement of kickout piston 33 must be slowedrelative to the downward or retracting movement of hold-down piston 53sufficiently to insure that hold-down arms 39 are retracted below therolling surfaces of mold run rails 22 before the mold is discharged ontosaid rails by kickout arms 20. To this end, the fluid line leading tothe upper end of each of cylinders 34 and 54 is provided with a knownform of adjustable flow control valve 82 which is so constructed as toadjustably restrict the velocity of flow away from the cylinder, but toallow fluid to flow relatively freely'toward the cylinder. Such valvesare commonly provided with adjustable means which restrict thecross-sectional area of the fluid passage for flow in one direction andwith a check or poppet valve arrangement which permits flow in theopposite direction to by-pass the restricted area.

If desired, a similar flow control valve 32 may be installed in the lineleading to the bottom of cylinder 34 so that the speed of the downwardor retracting movement of kickout plunger 33 maybe slowed sutlicientlyto prevent the mold from bumping spinning rollers 11 with excessiveforce as it is lowered.

The fluid supply line leading to the bottom of holddown cylinder 54 isnot provided with an adjustable flow control valve of the characterabove described, but preferably includes a normally open globe valve 83which can be closed to permit lowering or retraction of piston 33 ofkickout cylinder 34 without raising or extending piston 53 of hold-downcylinder 54, so as to facilitate maintenance and repair work on thekickout and hold-down mechanisms.

Although only one specific form of apparatus embodying the invention hasbeen described and illustrated in the accompanying drawings, it will beobvious that the invention is not limited either to the particularstructure shown or to use in the type of machine disclosed, but iscapable of a variety of mechanical embodiments. Various changes, whichwill now suggest themselves to those skilled in the art, may be made inthe form, details of construction and arrangement of the mechanicalparts, and in the electrical and fluid pressure means used forcontrolling the various elements of the apparatus, without departingfrom the spirit of the invention.

Reference is therefore to be had to the appended claims for a definitionof the limits of the invention.

What is claimed is:

1. In a machine for rotating a generally cylindrical article about itsaxis while said axis is in a substantially horizontal position, a safetydevice for preventing accidental ejectment of said article from themachine comprising a restraining member having an upper end adapted tobe positioned adjacent to the surface of said article to obstruct bodilymovement of said article while it is being rotated, means for movingsaid restraining member into and out of obstructing position including alinkage having one arm rotatable about a permanently fixed pivot andoperatively connected to the lower end of said restraining member and asecond arm rotatable about a movable pivot and operatively connected tosaid restraining member at a point intermediate its ends, means forapplying an actuating force to said first arm, and means for varying theposition of the movable pivot of said second arm so as to adjust theobstructing position of the upper end of said restraining member forcooperation with articles of different diameters.

2. In a machine for rotating a generally cylindrical article about itsaxis while said axis is in a substantially horizontal position, a safetydevice for preventing accidental ejectment of said article from themachine comprising a restraining member adapted to be positionedadjacent to the surface of said article to obstruct bodily movement ofsaid article while it is being rotated, means for moving saidrestraining member into and out of obstructing position including alinkage having one arm rotatable about a permanently fixed pivot andsecond arm rotatable about a movable pivot, means for applying anactuating force to said first arm, and means for varying the position ofthe movable pivot of said second arm so as to adjust the obstructingposition of said restraining member for cooperation with articles ofdifferent diameters, said last named means including a movable member onwhich said second arm is pivoted, means for moving said movable memberrelative to the fixed pivot of said first arm, a stop member having astepped surface adapted to engage and stop the movement of said movablemember, and means for adjusting said stop member to bring diiferentsteps into position to engage said movable member and thereby vary theposition at which the movement of said movable member is stopped.

3. In a machine for rotating a generally cylindrical article about itsaxis while said axis is in a substantially horizontal position of thetype wherein the article is delivered to and from the rotating mechanismby movement along a substantially horizontal path, a safety device forpreventing accidental ejectment of said article from the machinecomprising a restraining arm having a portion adapted to be positionedabove the upper surface of said article to obstruct bodily movement ofsaid article while it is being rotated, means' including a linkage forraising and lowering said restraining arm into and out of obstructingposition from and to a nonobstructing position located below said path,said linkage having a lifting arm and a pivot arm operatively connectedto said restraining arm at spaced points along the length thereof, saidlifting arm having a permanently fixed pivot and said pivot arm having amovable pivot, and means for varying the position of said movable pivotso as to adjust the obstructing position of said restraining arm forcooperation with articles of difierent diameters.

4. In a machine for rotating a generally cylindrical article about itsaxis while said axis is in a substantially horizontal position of thetype wherein the article is delivered to and from the rotating mechanismby movement along a substantially horizontal path, a safety device forpreventing accidental ejectment of said article from the machinecomprising a restraining arm having a portion adapted to be positionedabove the upper surface of said article to obstruct bodily movement ofsaid article while it is being rotated, means for raising and loweringsaid restraining arm into and out of obstructing position from and to anon-obstructing position located below said path, and means forcontrolling the relative speeds of raising and lowering movement of saidrestraining arm so that said arm may be lowered at a higher speed thanthat at which it is raised.

5. In a machine of the character described, the combination of means forrotating a generally cylindrical article about its axis while said axisis in a substantially horizontal position, rails on which said articleis adapted to roll along a substantially horizontal path toward and awayfrom opposite sides of said rotating means, said rails being positionedabove the level of said rotating means, means for lowering and raisingsaid article from and to the level of said rails to and from saidrotating means, a hold-down arm adapted to prevent accidental ejectmentof said article from said rotating means while said article is beingrotated, and means for moving said hold-down arm into and out of anoperative position, wherein the upper end of said arm is above saidrails and adjacent to the upper surface of said article, from and to aninoperative position below the level of said rails, said arm movingmeans including a linkage connected to said hold-down arm having one armrotatable about a permanently fixed pivot and operatively connected tothe lower end of said hold-down arm and a second arm rotatable about avertically adjustable pivot and operatively connected to said hold-downarm at a point intermediate its ends, means for applying actuating forceto said linkage, and means for varying the position of said adjustablepivot so as to adjust the operative position of said hold-down arm tocooperate with articles of different diameters.

References Cited in the file of this patent UNITED STATES PATENTS163,606 Peper May 25, 1875 522,093 Wolle June 26, 1894 1,783,094 Mooreet a1 Nov. 25, 1930 1,944,168 Camerota Jan. 23, 1934 2,570,325 DaltonOct. 9, 1951 2,671,260 Jessen et al. Mar. 9, 1954 2,751,617 McLagganJune 26, 1956 2,774,122 Hodler Dec. 18, 1956 FOREIGN PATENTS 345,502Great Britain Mar. 26, 1931 637,206 Great Britain May 17, 1950

